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No Power 1985 xr100

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I recently bought an xr100 that i thought I could get running but am having more issues than I thought I would. I have the bike running ok but whenever I get on the gas it just sputters and wants to die. If i rev it slowly it sounds fine, and i can even ride it, but as soon as I try to really get it moving it sputters and dies. Any ideas? I have replaced the carb already and still the same. Thanks for your help.

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Check and adjust the valves if out of spec

clean and adjust the points if out of spec and make sure the air filter is clean. Also, what did you replace the carb with, the same carb as what was on there or one of those Chinese things?

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How do you check and adjsust the valves? Is there a website that spells this out? Also I am not sure what the "points" are, could you tell me what those are?

I replaced the original carb with one i found on ebay and i bought 2. One for my bike and another for my bro's wifes bike. We both installed and his bike worked and mine didnt. We then switched the carbs thinking that maybe i just got a bad one but still the same thing; his worked and not mine.

Any other suggestions would be appreciated. Thanks

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Points..... You have a bad set of points or they are out of adjustment. Get a manual on adjusting the points and set them (some place around .015 or use a mach book cover). Buy a new set of points and a flywheel puller for the bike. Remove the ignition cover on the left side by the shifter. remove the nut for the flywheel and install the puller (just spend the $20 for the internal motorcycle specific puller as it will fit a ton of bikes) now, remove the flywheel. Remove the wire from the points and then the points (or pull the points then the wire which ever is easiest). Now re-install the wire on the new points (this is the easiest at this point) and install the points, when you tighten the screw only snug it up slightly so the points can be moved a bit. if you look at wherre the points mount you will see a slot that lines up with a slot on the motor, this is where you will put a standard screw driver and be able to adjust the points closed or opened once the flywheel is re-installed). now re-install the flywheel. turn the fly wheel over until the T mark on the outside edge of the flywheel lines up with the mark on the motor case (it is a mark on the motor right next to the flywheel on the top side of the case... kid of hard to explain, but if you are looking at the case half behind the flywheel you will see a little pointer or notch, this is the alignment notch that you line the T on the flywheel with (the T is for top dead center). now look thru the slots in the flywheel and find the points (flashlight at this point would be best used) you will see the points and that little slot I was talking about, insert a screw driver and turn the points one way or the other til they are open to about .015 or that match book cover. Adjust the points with the flywheel at TDC and the T lined up with the notch on the motor.once they are set, lock the screw that holds them down. roll the flywheel over a couple times and peer thru the slots in the flywheel to ensure the points are opening and closing, double check the gat at TDC again.

Now with the cover off, start the bike (keep fingers, toes and other items away from the flywheel) and see how it runs with a quick crack of the throttle. if it is not running better or is a little better, shut the bike off and adjust the points again, you might need to close them up to .010 or .008... Each bike is a bit different and likes a little bit different setting, also if you find that the points have to be closed up below .010 this is a sign that the spark plug coil is more than likely weak or the pulse coil is as the coil is requiring a longer dwell time to charge. Basically the points are closed the whole time until a little bump on the inside of the flywheel comes around and opens them, this causes the plug coil to discharge and fire the plug. if the coil is weak it requires longer dwell time of the points (time the points are closed) to properly charge. I have run into several XR100 in the 80's that had bad coils or weak ones.

Basically, a flywheel puller and a set of points will run you $25 and you will be good to go it that is the problem which is what it sounds like.

Typically if you are able to slow, slow, slowly roll the throttle on and it will run good, but if you crack it open quick it won't this is a sure sign on a points bike.

Let me know the out come. PM me and I will give you my number and walk you thru it.

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Thanks mkporn. I will try this out this weekend and get back to you to let you know how it goes. You said I could PM? you if I needed you to walk me through anything. What is that? Anyways thanks agian.

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Thanks mkporn. I will try this out this weekend and get back to you to let you know how it goes. You said I could PM? you if I needed you to walk me through anything. What is that? Anyways thanks agian.

PM means private message, just left click on his name and a drop down box will apear, then left click on "private message"

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Nice post. 👍

was that for me????? I have a warm fuzzy feeling in my tummy..... Thanks...🤣

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